/Engine/Plugins/Experimental/MeshModelingToolsetExp/Source/MeshModelingToolsEditorOnlyExp/Public/BspConversionTool.h
Updates the targets that the conversion functions operate on (BrushesToConvert, BrushForPivot), based on level composition, current selection, and settings. Also checks if this is a change from the previous value of BrushesToConvert.
true if BrushesToConvert changed.
bool CompareAndUpdateConversionTargets()